DE 195 15 121 C2 discloses a housing structure for electrical and/or electronic equipment installable outdoors. The outdoor housing structure comprises an inner cabinet and an outer cabinet spaced therefrom. A cooling air fan placed in the bottom of the outer cabinet sucks a cooling air flow out of the environment and into the outer cabinet, which is provided with upper outlets. An air heat exchanger in the inner cabinet, which is supplied the cooling air from the outer cabinet, and circulating fans ensure a recycled inside air flow. In addition, the electrical and electronic equipment are placed on cooling elements, which are held in the wall openings of the inner cabinet and are connected to the interior of the inner cabinet.
DE 102 10 418 A1 discloses a switch cabinet with a cooling device constructed as a rear wall and which has an air-to-water heat exchanger and blower. The partial hot air flows from the interior of the switch cabinet are subject to suction action and returned as cooled air, via a ventilating duct placed beneath the interior and an air retaining chamber on the front, to the interior of the cabinet.
A modular switch cabinet system according to DE 198 25 602 C2 is provided with a set of doors, which in each case have at least one fan, are replaceable and constructed for the reception of a cooling module, e.g. a compressor cooler, an air-to-air heat exchanger or an air-to-water heat exchanger in accordance with the given requirements.
DE 20 2004 006 552.5 U1 discloses an equipment and network cabinet, particularly a server cabinet, with electronic modular units, particularly servers located in the interior and an air-to-water heat exchanger placed in the lower cabinet area and which is connected to the cold water supply of the building.
As a result of air circulation with air paths of equal length and therefore identical flow resistances for the individual modular units and due to technical separation between the cold supply air and the heated exhaust air, it is possible to supply to the individual modular units cold supply air with an almost uniform supply air temperature. The removal of the heat loss of the electronic modular units received in a housing with a fan, takes place by means of a closed cooling air circuit, which has a supply air duct, particularly at the front and extending over the arrangement of the electronic modular units for the supply air cooled in the bottom air-to-water heat exchanger, as well as an exhaust air duct, which has behind the electronic modular units a first duct section for a rising exhaust air flow and a second duct section for a falling exhaust air flow and which is located in the rear door of the cabinet. The deflection of the exhaust air flow takes place with the aid of fans in the upper area of the rear door and advantageously the latter has a right-hand and a left-hand falling exhaust air duct through which exhaust air is supplied to the air-to-water heat exchanger.
U.S. Pat. No. 6,819,563 B1 discloses an equipment cabinet installable in a room for electronic equipment or components provided with a blower. Air conditioned ambient air is supplied for cooling the electronic components in this indoor equipment cabinet. The ambient air is cooled by means of an entrance heat exchanger located in the equipment cabinet and which is supplied with cooling water. The air then passes into the superimposed, stacked electronic equipment and is then returned as heated exhaust air to the installation room. In addition, an exit heat exchanger can be located in the equipment cabinet and cools the heated exhaust air before the latter is delivered to the ambient air.
In the equipment cabinet of US 2004/0100770 A1 the heat loss of superimposed electronic components is removed with the aid of blowers and combined air-liquid cooling. On at least one side of a cabinet an air-to-liquid heat exchanger is installed. Blowers are located in a separate housing and are connected to the reception area. Alternatively, the air-to-liquid heat exchanger units can be arranged in the form of a front and rear door. A closed cooling air circuit is made possible by the formation of a supply or removal area in the doors, as well as a connecting area below and/or above the stack arrangement. Additional fans can be located in the supply and removal areas. The heat exchanger doors are articulated to the cabinet body for accessing the reception area and electronic components and equipment.
DE 102 10 417 B4 describes an arrangement for cooling a switch cabinet in which the heat loss of superimposed, heat-generating components is removed with the aid of a heat exchanger rear wall or a rear wall heat exchanger cabinet and a cooling air flow of a central cooling installation. The cooling air flow of the central cooling installation passes from a double bottom below the switch cabinet into a frontally constructed supply air shaft. The heated exhaust air is cooled with the aid of downstream fans in the heat exchanger rear wall or rear wall heat exchanger cabinet using an air-to-water heat exchanger and is either returned to the double bottom below the switch cabinet or to the switch cabinet ambient air. The central cooling installation supplies both the switch cabinet ambient air and the double bottom and consequently, the interior of the switch cabinet with cooling air, so that a relatively complicated control arrangement is necessary to achieve the necessary cooling capacity in each case.
WO 01/72099 A2 and US 2001/0042616 A1 disclose a cooling system for equipment and network cabinets serving to flexibly and effectively remove the heat loss of high power, densely packed, electronic modular units in a plurality of cabinets strung together in an installation area or room. The cooling system is intended to supplement the room air conditioning and make it less expensive, in that the exhaust air heated in a cabinet is supplied by fans to an air-to-fluid heat exchanger, cooled to ambient temperature and delivered to the ambient air. The fans and heat exchanger are housed in an additional housing fixed to the rear of the cabinet. The exhaust air from the cabinet passes via an opening in the cabinet rear wall or door and a complementary opening in the engaging heat exchanger fan housing into the interior of the housing. The air is guided by means of the air-to-fluid heat exchanger in the vicinity of the housing opening by means of downstream fans, and via the housing outer wall, is delivered to the environment.
According to a data sheet of the applicant of WO 01/7209912 and US 2001/0042616 A1, Messrs. Liebert, Columbus, Ohio 43229, USA: RackCooler, System Configuration Guide, drawing number 171439, rev. 07, Jun. 12, 2002, pp 1 to 8 and the associated installation manual SL-16810 (9/01), pp 1 to 10, the so-called RackCooler, i.e. the housing unit with an air-to-water heat exchanger and superimposed fans is fixed externally to the rear door of cabinets, and cooling water delivering the absorbed heat loss outside the cabinet installation area, is supplied to each RackCooler by means of a ground-installed pipe system and connecting hoses between the pipe system and each RackCooler. Disadvantages of the retrofitting of existing doors are system downtimes during retrofitting, possible overloading of existing closure and hinge elements, low efficiency relative to the space requirement due to the restriction of the areas available for cooling purposes due to taking account of existing closure and hinge means, and a relatively small opening angle of the retrofitted door.
The connecting hoses extending from the bottom-side connection points to the connections on each RackCooler must, due to the placing of the RackCooler on the rear doors, have a relatively flexible construction and must be able to follow the swinging movement of the doors. Therefore, the disadvantage arises of the connecting hoses only having an inadequate mechanical stability and robustness. The hoses also lack the necessary gas-tightness, so that due to gas diffusion, corrosion of the heat exchanger pipes can take place.